The above-identified related patent application discloses a fork-type ceiling sprinkler which includes a pair of arms extending away from the sprinkler body on an outlet side of the body. The fork-type sprinkler disclosed differs from a conventional frame-type sprinklers in that the arms of the fork do not come together directly or with a cross member opposite the outlet. The only function of the arms disclosed in the related application is to support a drop-down deflector aligned with the outlet. As a result of this design, water or other fire-retarding fluid delivered by the sprinkler flows unrestrictedly and uninterruptedly from the outlet directly onto the deflector, eliminating a frame shadow in the dispersion of the fluid. A plug is sealingly retained in the outlet by means of a lever assembly which couples to the sprinkler body itself. Thus, no significant system loads are imposed upon the arms except to support the deflector after sprinkler activation. This design permits the use of forks and deflectors which are less expensive to fabricate than frames and frame supported deflectors. Either or both pieces can be provided by stamping, rather than a more costly casting or machining process typically used for the latter.
While the original design disclosed in the related, above-identified application offers the combined advantages of low fork/deflector cost and good fluid distribution without frame shadow, the latter can constitute an advantage in and of itself. Moreover, the lever assembly disclosed in the related patent application is relatively complex, incorporating two major lever elements, each with a number of cutouts, tabs and bores and an adjustment screw to adjust the pressure provided by the levers against the plug.
The present invention is directed to solving the problem of simplifying the lever construction of my earlier invention, while retaining the benefit of a shadow free fluid distribution pattern provided by a fork-type deflector mounting.